• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.47-53
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• 2019

Safety accidents at industrial sites can occur anytime, anywhere. Recently, research on the industrial safety management system based on the IoT has been actively conducted. However, most of the studies are studies of actions after safety accidents or simply monitoring. In this paper, the safety equipment was introduced before safety accidents occurred, and the subjects could be managed not only by workers but also by visitors. Also, it implements a system to prevent the accident by detecting the user's motion and situation periodically before a safety accident occurs. The implemented system is a system that attaches the device for safety management to the hard hat and can identify the safety situation by using the Bluetooth beacon device attached to the user's smartphone and the industrial site.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.1
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• pp.67-74
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• 2011

The study was constructed an analysis of postures of a expert diver's wearing and taking off with skinscuba equipment using ergonomics tools(REBA, RULA, OWAS) for prevention of Musculoskeletal injuries. This survey is consisted of 4 postures in terms of wearing and taking off : Crouching(alone), Standing(alone), Helping of assistance, Using of stanchion. Their rate of injuries is getting higher due to instability postures, exposed dangers and excessive physical actions. So this study provides basic and educational information for prevention of that. The result is as follows : The result of crouching postures of wearing alone was REBA 9(Ac Level 3), RULA 7(Ac Level 4), OWAS AC 2, and crouching postures of taking off alone was REBA 12(Ac Level 4), RULA 7(Ac Level 4), OWAS AC 4. The result of standing postures of wearing alone was REBA 8(Ac Level 3), RULA 7(Ac Level 4), OWAS AC 3, and standing postures of taking off alone was REBA 8(Ac Level 3), RULA 7(Ac Level 4), OWAS AC 3. The result of helping of assistance postures of wearing was REBA 4(Ac Level 2), RULA 3(Ac Level 2), OWAS AC 2, and standing postures of taking off alone was REBA 4(Ac Level 2), RULA 4(Ac Level 2), OWAS AC 1. The result of using of stanchion postures of wearing was REBA 3(Ac Level 1), RULA 3(Ac Level 2), OWAS AC 1, and standing postures of taking off alone was REBA 3(Ac Level 1), RULA 3(Ac Level 2), OWAS AC 1. Especially both postures of wearing and taking off alone showed high results in the analysis of postures using ergonomics tools(REBA, RULA, OWAS).

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.1-9
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• 2021

The hologram pyramid is an application of floating holograms, allowing the observer to see three-dimensional holograms from various angles without wearing wearable devices. Due to the low cost and ease of manufacturing, it has been used in a wide variety of fields as diverse as education, prototyping, showcase, and etc. But, when the observer looks at the hologram from the place where each side of the hologram pyramid is connected, the hologram looks cut and distorted. Also, the observer can see the only hologram of angles viewed head-on from each side. In this paper, we propose a method of generating a hologram image corresponding to the observer's gaze angle by tracking the observer's position and conducting reverse distortion. It provide a hologram of the angle viewed by the observer without cutting and distortion. In addition, the existing method and the proposed method were applied and compared in the hologram pyramid.

• The Korean Journal of Emergency Medical Services
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• v.25 no.1
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• pp.23-36
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• 2021

Purpose: The purpose of this study was to determine how the use of level D personal protective equipment (PPE) and cardiopulmonary resuscitation (CPR) feedback equipment affects chest compression (CC). Furthermore, this study provides basic data for developing Korean CPR guidelines that can be applied to patients with suspected or confirmed COVID-19. Methods: This randomized, single-blinded, crossover simulation trial included 26 student paramedics who performed 2-minute chest compressions using three different methods: Method A involved performing traditional CC for two minutes without donning level D PPE, Method B involved performing CC while donning level D PPE, and Method C involved performing CC with a CPR feedback device while donning level D PPE. Results: The use of a CPR feedback device during the 2-minute CC increased the exercise intensity of the subjects, but donning level D PPE didn't affect the quality of CC and the exercise intensity. The results of methods A and B showed changes in the quality of compression 80 seconds after the start of CC. No significant changes occurred in 2-minute CC when using the CPR feedback device. Conclusion: Using a CPR feedback device could prevent deterioration in the quality of CC while donning level D PPE.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.4
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• pp.171-176
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• 2023

In the modern society of the 21st century, portable electronic products using secondary batteries are continuously becoming lightweight and miniaturized. And along with this trend, we are active in the era of the Fourth Industrial Revolution, where we collect and share information in our daily lives using wearable electronic devices. Therefore, the role of secondary batteries that can be recharged while using small home appliances and digital devices is increasingly important. Along with this increase, secondary battery performance tests require various test methods such as characteristics, lifespan, failure diagnosis, and recycling. In addition, the construction of a battery test system to ensure the safety and proper functioning of the battery, along with guidelines and correct basic knowledge are being considered. Therefore, in this paper, we will examine the characteristics of the secondary battery Li-ion battery according to the charging and discharging scenarios directly connected to the performance of the battery.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.43-52
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• 2023

Traffic accidents among children have been decreasing after the installation of yellow carpets. However, the explanatory power of the causal relationship between yellow carpet installation and traffic accidents is still insufficient. The yellow carpet effect was analyzed in greater depth using virtual reality (VR) simulation experiments in various situation that could not be evaluated in existing actual vehicle research studies due to difficulties or risks in implementation. A target site where an actual yellow carpet was installed was selected and, implemented into a virtual environment. Subjects were made to, were gaze measurement equipment and ride the simulator. The visual/driving behavior before and after yellow carpet installation was compared, and a t-test analysis was performed for statistical verification. All the results were found to be statistically significant.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.1-7
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• 2023

The advent of deep learning technologies has led to the development of various medical applications, making healthcare services more convenient and effective. Among these applications, heart rate estimation is considered a vital method for assessing an individual's health. Traditional methods, such as photoplethysmography through smart watches, have been widely used but are invasive and require additional hardware. Recent advancements allow for contactless heart rate estimation through facial image analysis, providing a more hygienic and convenient approach. In this paper, we propose a lightweight methodology capable of accurately estimating heart rate in mobile environments, using a specialized 2-channel network structure based on 2D convolution. Our method considers both subtle facial movements and color changes resulting from blood flow and muscle contractions. The approach comprises two major components: an Encoder for analyzing image features and a regression layer for evaluating Blood Volume Pulse. By incorporating both features simultaneously our methodology delivers more accurate results even in computing environments with limited resources. The proposed approach is expected to offer a more efficient way to monitor heart rate without invasive technology, particularly well-suited for mobile devices.

• Journal of Chest Surgery
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• v.36 no.6
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• pp.391-396
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• 2003

Background: Recently transilluminated powered phlebectomy was introduced and used as a method of surgical treatment for varicose vein in lower extremities. The advantage of transilluminated powered phlebectomy are minimal scar and good cosmetic effect. However, the disadvantages of transilluminated powered phlebectomy is that a high priced Trivex system must be used which increases the patient's expenses. Therefore, we performed a transilluminated powered phlebectomy using an existing arthroscopic equipment instead of Trivex system and observed the effect of treatment and efficiency of the treatment. Material and Method: From March, 2000 to February, 2003, 78 patients (113 limbs) underwent transilluminated powered phlebectomy with an arthroscopic equipment. Patient's disease history, the number of operative scars and complications were reviewed. Result: The operation was performed in 133 limbs of the 78 patients (34 men, 44 women) and the age of patients were ranged from 16 to 72 years with mean age of 41.8 years. Operative time ranged from 20 to 65 minutes (average 48.7 minutes) per limb. The number of operative scar per limb from 2 to 7 (average 4.9). Postoperative complications are transient ecchymosis (78 cases) that desappeared spontaneously, edema persisting longer than 3 weeks (6 cases), remnant varicose vein (4 cases), skin perforation during operative procedure (2 cases), and contact dermatitis due to compression stocking (4 cases) The mean hospitalization day was 3.09 days. Subjective mean satisfaction degree of operation by the patients using a visual analogue scale was 92.6%. Conclusion: Our findings demonstrated that transilluminated powered phleectomy using arthroscopic equipment was possible and had good cosmetic results with acceptable complications.

• Journal of radiological science and technology
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• v.34 no.3
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• pp.209-214
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• 2011

Goal of this study was to measure effective radiation dose of highly exposed patients who were treated by TACE, interventional radiology from June to September 2010. The effective radiation dose was approximately measured by weighted DAP (dose area product) with the ionization chamber which is inserted in angiography equiment (Philips Allura Xper FD 20). Radiation dose was measured by TLD which was attached to patients' thyroid and genital gland. The average of ED (effective dose) was 18.43${\pm}$6.63 mSv per person and the average of radiation dose of thyroid and genital gland was 0.37 mSv, 0.77 mSv, respectively. The mean radiation dose of operators who wear the protector was 0.07 mSv for thyroid, and 0.01 mSv for genital gland, respectively. All staffs involved in TACE treatment, have to keep them aware and use the appropriate protectors to reduce the radiation dose of patient.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.115-115
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• 2010

고휘도 고효율 백색 LED (lighting emitting diode)가 차세대 조명광원으로 급부상하고 있다. 백색 LED를 생산하기 위한 공정에서 MOCVD (유기금속화학증착)장비를 이용한 에피웨이퍼공정은 에피층과 기판의 격자상수 차이와 열팽창계수차이로 인하여 생성되는 에피결함의 문제로 기판과 GaN 박막층 사이에 완충작용을 해줄 수 있는 버퍼층 (Buffer layer)을 만든다. 그 위에 InGaN/GaN MQW (Multi Quantum Well)공정을 하여 고휘도 고효율 백색 LED를 구현 할 수 있다. 이 공정에서 기판의 온도가 불균일해지면 wafer 파장 균일도가 나빠지므로 백색 LED의 yield가 떨어진다. 균일한 기판 온도를 갖기 위한 조건으로 기판과 induction heater의 간격, 가스의 흐름, 기판의 회전, 유도가열코일의 디자인 등이 장비의 설계 요소이다. 본 연구에서는 유도가열방식의 유도가열히터를 이용하여 기판과 히터의 간격에 차이에 따른 기판 균일도 측정했고, 회전에 의한 기판의 온도분포와 자기장분포의 실험적 결과를 상용화 유체역학 코드인 CFD-ACE+의 모델링 결과와 비교 했다. 또한 가스의 inlet위치에 따른 기판의 온도 균일도를 측정하였다. 본 연구에서 사용된 가열원은 유도가열히터 (Viewtong, VT-180C2)를 사용했고, 가열된 흑연판 표면의 온도를 2차원적으로 평가하기 위하여 적외선 열화상 카메라 (Fluke, Ti-10)를 이용하여 온도를 측정했다. 와전류에 의한 흑연판의 가열 현상을 누출 전계의 분포로 확인하기 위하여 Tektronix사의 A6302 probe와 TM502A amplifier를 사용했다. 흑연판 위에 1 cm2 간격으로 211곳에서 유도 전류를 측정했다. 유도전류는 벡터양이므로 $E{\theta}$를 측정했으며, 이때의 측정 방향은 흑연판의 원주방향이다. 또한 자기장에 의한 유도전류의 분포를 확인하기 위하여 KANETEC사의 TM-501을 이용하여 흑연판 중심으로부터 10 mm 간격으로 자기장을 측정 했다. 저항 가열 히터를 통하여 대류에 의한 온도 균일도를 평가한 결과 gap이 3 mm일때, 평균 온도 $166.5^{\circ}C$에서 불균일도 6.5%를 얻었으며, 회전에 의한 온도 균일도 측정 결과는 2.5 RPM일 때 평균온도 $163^{\circ}C$에서 5.5%의 불균일도를 확인했다. 또한 CFD-ACE+를 이용한 모델링 결과 자기장의 분포는 중심이 높은 분포를 나타냄을 확인했고, 기판의 온도분포는 중심으로부터 55 mm되는 곳에서 300 W/m3로 가장 높은 분포를 나타냈다. 가스 inlet 위치를 흑연판 중심으로 수직, 수평 방향으로 흘려주었을 때의 불균일도는 각각 10.5%, 8.0%로 수평 방향으로 가스를 흘려주었을 때 2.5% 온도 균일도 향상을 확인했다.